noun
dry river; wadi; arroyo
Refers to a riverbed that is normally dry except after heavy rain; often used for seasonal streams in arid regions.
この水無川は、大雨のときだけ水が流れる。
This dry river only flows when there is heavy rain.
砂漠の水無川をワジと呼ぶ。
A dry river in the desert is called a wadi.
Compound of 水 (mizu, 'water') + 無し (nashi, 'without') + 川 (kawa, 'river'), literally 'waterless river'. The reading みずなしがわ is standard; みなしがわ is a contracted form.